Spraying apparatus



Aug. 2, 1932. K. A. MILAR ET AL SPRAYING APPARATUS Filed March 22, 1950 ll [L A Qfnven Z0745 /fai"l .65 Ml Zar Harman Z. Cline/'7 Patented Aug. 2, 1932 means UNITED STATES PATENT oFFicE it KAEL A. MILAR, OF CHICAGO, AND DUNCAN L. CLINCH, OF HUBBARD WOODS, ILLINGIS,

ASSIGNORS, BY MESNE .ASSIGNIV'IENI'S, OF 0NE-HALF TO DUNCAN I. CLINCH, 0F, HUBBARD WOODS, ILLINOIS, AND ONE-HALF T6 KARL A. MILAR, OF, CHICAGO,

ILLINOIS Application filed March 22,

This invention relates to spraying apparatus.

Great ditficulty has heretofore been experienced in the spraying of certain classes of material having solid matter therein, such as asbestos fiber, due to clogging in the spray gun. The usual practice has been to frequently clean out the gun but on account of the rapidity with which the gun clogs, a large amount of .time is lost, thus increasing the labor charge and, further, it is ditficult to properly clean out the gun because of inaccessibility to the interior, the usual small discharge opening employed in the gun and on account of the lowered air pressures available at the gun.

One object of our invention is to provide a spraying apparatus particularly designed for the handling of materials containing socalled solid matter, such as asbestos fiber, wherein danger of clogging of the spray gun is reduced to a minimum.

Another object of the invention is to provide an arrangement of spraying apparatus using a pressure supply tank for the material, wherein the material is strained or screened to the desired degree at a point adjacent the tank, in combination with pipes and valves so arranged that the strainer may be readily cleaned without the necessity of making any disconnections of any fittings and by utilizing the same source of air pressure used for spraying the material. I

A specific object of the invention is to provide an improved strainer usable in apparatus of the type indicated.

In the drawing forming a part of this specification, Figure 1 is a schematic view illustrating the spraying apparatus embodylng our improvements. Figure 2 is a vertical sectional view of the improved strainer. And Figure 3 is another vertical sectional view of the strainer, the two sections being improvements in at right angles to each other.

In said drawing, 10 indicates the main pipe for supplying air under pressure, such as a yard line pipe in railroad shops, and from which leads an air inlet pipe 11 to the pressure supply tank 12, the latter being mounted in any'suitabl-e manner on supports 1318.

SPRAYING APPARATUS 1930. Serial No. 437,990.

Included in the air inlet pipe 11 isa control valve 13 and two Ts 14c and 15.

From the T 14 extends a branch pipe 16 which is in communication with a pressure gauge 17 and ya safety valve 18. b As will be evident, the tank 12 is sealed and is adapted to have the material tobe sprayed entered therein through a plug cap 19 in the top thereof. Sediment may be drained from the tank by removing a bottom plug 20, as will be understood. Extending within the tank and substantially to the bottom thereof is the material delivery pipe 20, which has included therein, in the order named, a valve 21, a. strainer designated generally by the referencech'aracter A, a four-way fitting 22, andanother valve 23. The main length of the'delivery pipe, beyond the valve 23', will preferably be in the form of a flexible hose 24 leading to the spray gun 25, the latter being indicated diagrammatically. In actual practice, a second source of compressed air willbe supplied to the gun 25, through a flexible hose 26, which leads direct to the main line 10, so that the air delivered to the gun for actual spraying purposes, that is, for atomizing the material at the gun, will be delivered to the gun under the main line pressure and not at a reduced pressure, as might otherwise occur, if the secondary air supply were taken from the air inlet pipe 11.

In carrying out our invention, we provide a by-pass around the tank and strainer, in the form of a pipe 27 leading from the T 15 and ultimately entering the delivery pipe 20 at the fitting 22. Included in said bypass is a valve 28, a T29 and a second valve 30. Connected with the T29 is a bleed valve 31. Communicating with the four-way fitting 22 is a pipe 32 having a valve 33 therein and a coupling 34, this connection being provided for the purpose of supplying either steamor hot air to blow out the delivery pipe in cold weather, when the material has a tendency to coagulate. The strainer A, the details of which are described hereinafter, has a bleed or discharge valve 35 at its underside.

In the operation of our apparatus, while 100 spraying, the valves 13, 21, 23 and 31 will be open while the valves 28, 30, 33 and will be closed. Under this condition of the parts, it is evident that air under pressure sup glied to the top of the tank will force the material up through the pipe 20, through the screen box A and to the spray gun 25, and the material will be screened at the box A, so as to strain out foreign matter and/or such larger particles of the solid matter in the spray material as would not properly pass through the spray gun.

When it is desired to clean out the strainer box A, and which may be done without making any disconnection whatsoever in the layout, the valves 13, 28, 30 and 35 will be open, while, at the same time, the valves 31, 21, 23 and 33 will remain closed. The strainer box A may also be cleaned out by introducing hot air or steam through the valve 33 when open, valves 21, 23 and 30 being closed and valve 35 also open.

Under such condition of the parts, the air is passed through the by-pass line 27 into the material delivery line at the fitting 22, thence backward along the material line into the strainer box A and such solids as have been caught on the incoming side of the screen will then be forced out of the strainer box A through the discharge valve 35, the discharge being caught in a bucket or the like, as will be understood. In this manner, it is evident that a minimum amount of time is required in cleaning the strainer box and the material supply line to the gun is kept clear at all times, thereby promoting the ei'rlciency of the apparatus and reducing to an absolute minimum the loss of time required in keeping the line clear. When hot air or steam is to be utilized, it will be supplied by opening the valve 33 and introducing the hot air or steam to the delivery line while the valves are in the condition first described for supplying the material to the spray gun.

The strainer, shown in detail in Figures 2 and 3, preferably comprises a rectangular casing or box 36 having aremovable top cover 37. Preferably interposed between the cover 37 and the main portion of the box will be a sealing gasket 38, the cover being tightly held by suitable means, such as the swivel bolts 3939 and nuts 40-l0, the bolts passing through slots ilt1 at the ends of the cover, in a well known manner.

On the interior of the box 36 and extending along the front, back and bottom walls thereof, are two spaced ribs 42l:2 which provide a vertical channel or guide for the removable screen or perforated partition e 3, it being evident that said screen is removable from the top of the box when the cover is off and that it forms a complete perforated artition between the top and bottom of the ox when in place. As will be understood. the openings in the screen 43 will be made 01:

such size as to hold back all solid particles of a size larger than that which can be passed through the spray gun without clogging. As shown clearly in Figure 2, the screen 43 is located appreciably nearer the outlet side of the box than the inlet side, so that a larger chamber is formed on the intake side of the screen than on the outlet side, thus promoting the tendency of the larger particles to settle to the bot-tom. The bottom wall has an outlet M communicating with the larger chamber of the box, said outlet H being controlled by the bleed or discharge valve hereinbefore mentioned.

As previously described, when the by-pass is used to clean the strainer box, the air under pressure will come in from the righthand side of the screen L3 as viewed in Fig *re 2, and will dislodge from the intake side of the screen, such large particles as may have collected thereon or within the openings, and force the same out through the discharge pipe i l.

From the preceding description, it will be seen that the screenings may be cleared out without disconnecting any of the piping; that the screen or strainer box may be cleaned if desired, by removal of the cover, and that screens with differentsize openings may be employed in accordance with the different characters of material being sprayed o have herein shown and described what we now consider the preferred manner of carrying out the invention, but the same is merely illustrative and we contemplate all changes and modifications that come within the scope of the claims appended hereto.

e claim:

1. In a. sprayin apparatus, the combination with a pressure tank for the material and having an air inlet pipe and a material outlet pipe; a strainer having inlet and outlet ports, a bleed valve independent of either of said ports, located in said outlet pipe; a

by-pass from the inlet pipe direct to the out-- let pipe and connected with the latter on the outletside of the strainer; and control valves arranged to shut off the delivery of the mate rial and bypass the air through the strainer direct to the bleed valve to clean the strainer.

2. In a spraying apparatus, the combina tion with an air pressure tank for the material and having an air inlet pipe and a material outlet pipe, the latter having included therein a valve, a strainer, and a second valve, in the order named, from the tank; and means independently of the air line that delivers air to the tank, for introducing hot air or steam into said delivery pipe.

3. In a spraying apparatus, the combination with a pressure tank for the material and having an air inlet pipe and a material outlet pipe, the latter having included therein a valve, a strainer, and a second valve, in the order named, from the tank; means for introducing air into said delivery pipe at a point intermediate the strainer and said second valve, the strainer having a discharge opening whereby, upon closing ofsaid valves and the introduction of air into said delivery pipe, the strainer may be discharged through its discharge opening; and means for introducing hot air or steam into said delivery pipe onthe outlet side of the strainer indedendently of said means for introducing air.

4. Ina spraying apparatus, the combination with a tank for containing the material to be sprayed; means for supplying air under pressure thereto; a discharge pipe from the tank having a valve, a strainer, and a second valve, in the order named, from the tank, therein; said strainer having a control discharge opening; and a by-pass from the air inlet pipe to the delivery pipe communicating with the latter intermediate the strainer and the second named valve therein, said bypass having two valves therein whereby, upon opening of said two valves in the by-pass, the closing of the two valves in the delivery pipe, and the opening of the discharge of the strainer, the latter may be cleaned by air under direct pressure from the air line passing therethrough.

5. In a spraying apparatus, the combination with an air pressure tank for the mate rial and having an air inlet pipe and a material outlet pipe; of a strainer having inlet and outlet ports and a valved discharge port independent of said inlet and outlet ports, said strainer being included in the outlet pipe line; valves in said outlet pipe line on opposite sides of the strainer; and means for introducing air under pressure into said outlet pipe line at a point intermediate the outlet port of the strainer and the adjacent valve in said pipe line, whereby upon closing said valves in the pipe line and opening the valve for the discharge port of the strainer and introducing air into said delivery pipe line, the strainer may be directly discharged through said discharge port.

6. In a spraying apparatus,-the combination with an air pressure tank for the material having an air inlet pipe and a material outlet pipe, said outlet pipe having a strainer included therein and the strainer having a discharge opening; of means for introducing air into said delivery pipe outwardly of the strainer and whereby the latter may be discharged through its discharge opening; and separate means for introducing hot air or steam into said delivery pipe.

In witness that we claim the foregoing we have hereunto subscribed our names this 13th day of March, 1930.

KARL A. MILAR. DUNCAN L. CLINCH. 

